I learn Japanese by watching 深夜食堂 myself. In the introduction of an episode, the main character says "あとはかってにちゅうもんしてくれりゃ".
I am able to figure out the meaning of the whole sentence by watching translated subtitle. However, I have no idea when and how to use the phrase "してくれりゃ".
So, what is the modality when you use "してくれりゃ"? How to use it correctly ?